Without limiting the scope of the present disclosure, its background is described in connection with external fixation devices. Generally, external fixation devices are commonly used on both the upper and lower limbs for both adults and children in a variety of surgical procedures including limb lengthening, deformity correction and treatment of fractures, mal-unions, non-unions and bone defects.
One common external fixation device is known as the Ilizarov Apparatus. The Ilizarov external fixation procedure involves a rigid framework consisting of several rings or arches that are placed externally around the limb and attached to injured (e.g., due to fracture) or surgically separated (e.g., for limb lengthening and deformity correction) bone segments using special bone fasteners (wires and pins) inserted into the bone segment and connected to the related section of the external rigid framework. The opposite rings of the rigid framework are connected by either threaded or telescopic connection rods or by assembled uni-planar or multi-planar angular hinges, which allow the surgeon to adjust the relative position of the rings to each other longitudinally or angularly over a period of time. This allows new bone to gradually form in the gap between bone segments created by this distraction technique. Once the desired position of bone segments is achieved over the course of time (e.g., 2-6 weeks), the external apparatus is stabilized into a fixed position and left on the bone segments until the fracture is healed or newly formed bone is completely or substantially mineralized, which could take up to an additional 3-6 months, depending on the nature of pathology and degree of deformity.
Another common external fixation device is a Taylor Spatial Frame as described in U.S. Pat. Nos. 6,030,386, 5,891,143, and 5,776,132. The Taylor Spatial Frame is a hexapod type of device based on a Stewart platform but shares many components and features of the Ilizarov apparatus. The Taylor Spatial Frame consists of two external fixator rings attached to bone segments by wires or half pins and connected together by six struts that may be lengthened or shortened as necessary. Adjustment of strut lengths allows manipulation of the bone segments in 6 axes (e.g., lengthening/shortening, external/internal rotation, anterior/posterior horizontal translation, medial/lateral horizontal translation, anterior/posterior angular translation, and medial/lateral angular translation) to correct linear, angular and rotational deformities simultaneously.
The fixation device would usually be placed on the affected patient by medical personnel in such a way as to align the affected body part during the healing process, holding the affected body part in the proper position for treatment. Since applications of such devices can include a wide variety of deformities, body sites, and surgical implementations, there is a need for fixation devices that can initially be acutely adjusted in order to accommodate such variabilities and subsequently maintain the affected body part in one desirable position. Moreover, a typical treatment regimen requires frequent adjustments to be performed by the patient and/or during repeated visits to medical professionals so that the fixation device could be periodically and gradually adjusted, providing the desired orientation to the affected body part and setting the proper amount of stretching and support for healing. Accordingly, there is also a need for fixation devices that allow for gradual adjustments after the fractured body part is substantially maintained in one position.
Thus, there is a need for an improved fixation device that will allow medical professionals to make effective, calibrated adjustments to the positioning of the injured body part.